Effect of delivering light in specific narrow bandwidths from 394 to 515nm on the micro-hardness of resin composites.

Objectives: This study investigated the wavelength-dependent photosensitivity of eleven resin composites (Admira A2, Heliomolar A2, Herculite XRV A2, Pyramid Dentin A2, Solitaire 2 A2, Z250 A2, AElite LS A2, Vit-l-escence A2, Tetric Ceram Bleach XL, Tetric Ceram A2, Pyramid Enamel Neutral).

Methods: Resin composites 1.6mm thick were exposed to narrow bandwidths of light at the following peak wavelengths: 394, 400, 405, 410, 415, 420, 430, 436, 442, 450, 455, 458, 467, 470, 480, 486, 493, 500, 505, and 515+/-5nm.

Third-generation vs a second-generation LED curing light: effect on Knoop microhardness.

Third-generation light-emitting diode (LED) curing lights use several different types of LEDs within the light to deliver a broader spectral output compared with the narrower spectral output of second-generation curing lights. This study determined the benefits of this broader spectral output. A third-generation LED curing light was modified so that the 4 peripheral LEDs, which provide the lower wavelengths, could be turned on or off, allowing the light to be used as a third- or a second-generation LED curing light.

Effect of reduced exposure times on the microhardness of 10 resin composites cured by high-power LED and QTH curing lights.

Purpose: To compare the effect of reduced exposure times on the microhardness of resin composites cured with a "second-generation" light-emitting diode (LED) curing light and a quartz-tungsten-halogen (QTH) curing light.

Methods: Ten composites were cured with a LED curing light for 50% of the manufacturers" recommended exposure time or a QTH light at the high power setting for 50% of the recommended time or on the medium power setting for 100% of the recommended time. The composites were packed into Class I preparations in extracted human molar teeth and cured at distances of 2 or 9 mm from the light guide.

Evaluation of a dual peak third generation LED curing light.

This study compared 3 light-emitting diode curing lights (UltraLume 5, FreeLight 2, LEDemetron I) with a quartz-tungsten-halogen light (Optilux 401) to determine which was the better at photopolymerizing 5 resin composites. The composites were 2 mm thick and were irradiated for the manufacturers' recommended curing times at distances of 2 mm and 8 mm from the light guide. The Knoop hardness at each of 22 points over a 10-mm diameter footprint at the top and bottom of the composites was used to compare the lights.

Knoop hardness of ten resin composites irradiated with high-power LED and quartz-tungsten-halogen lights.

This study compared a high-power light-emitting-diode (LED) curing light (FreeLight 2, 3M ESPE) with a quartz-tungsten-halogen (QTH) light (TriLight, 3M ESPE) to determine which was the better at photo-polymerising 10 resin composites. Class I preparations were prepared 4-mm deep into human teeth and filled with 10 different composites. The composites were irradiated for 50% or 100% of their recommended times using the LED light, and for 100% of their recommended times with the QTH light on either the high or medium power setting.

Effects of resin composite composition and irradiation distance on the performance of curing lights.

This study determined the effect of using five resin composites and two irradiation distances to test the performance of dental curing lights. Three types of curing lights with similar spectral distributions, but each delivering a different power density, were used for irradiation times ranging from 3 to 60 s. Power densities were measured at 2 and 9 mm from the tip of the light guide.

The effect of distance from light source on light intensity from curing lights.

Purpose: To investigate how light intensity changes as the distance increases from the tip of the light guide.

Materials And Methods: Ten different curing light/light guide combinations were used. Light intensity was measured at 0, 3, 6, and 10 mm from the tip of the light guide with a radiometer.

Effect of disposable infection control barriers on light output from dental curing lights.

Purpose: To prevent contamination of the light guide on a dental curing light, barriers such as disposable plastic wrap or covers may be used. This study compared the effect of 3 disposable barriers on the spectral output and power density from a curing light. The hypothesis was that none of the barriers would have a significant clinical effect on the spectral output or the power density from the curing light.

Comparison of quartz-tungsten-halogen, light-emitting diode, and plasma arc curing lights.

Purpose: This study determined which light source was best at photopolymerizing five representative brands of resin composite. The hypothesis was that there would be no difference in the hardness of the composites when irradiated by any of the lights.

Materials And Methods: Six curing light/tip combinations were used to photopolymerize five resin composites.

Evaluation of a second-generation LED curing light.

Background: Light-emitting diode (LED) curing lights offer advantages over quartz-tungsten-halogen (QTH) lights, but the first-generation LED lights had some disadvantages.

Purpose: This study compared a second-generation LED light with a QTH light to determine which was better at photopolymerizing a variety of resin composites.

Methods: The ability of a LED light used for 20 and 40 seconds to cure 10 resin composites was compared with that of a QTH light used for 40 seconds.